Safety apparatus for rail vehicles



July 27, 1937.

T; H. SCHOEPF ET AL. 5 SAFETY APPARATUS FOR 'RAIL VEHICLES Filed'Feb. 17,1936 7 2 Sheets-Sheet 1 w. rs N km F WW 0 r v mm 5 M08. v R Qw wm July 27, 1937. H' ET 2,088,485

SAFETY APPARATU FOR RAIL V EHICLES "2 Sheets-Sheet 2 Armin/5y;

Patented July 27, 1937 UNITED STATES.

PATENT oFFicE cinnati, Ohio,

assignors to The Cincinnati Traction Building 00., Cincinnati, Ohio, a corporation of Ohio Application February 17, 1936, Serial No. 64,295

30 Claims. (01. 246--169) 1 Our invention relates to safety apparatus and particularly to such apparatus as applied to rail cars.

The particular object of our invention is to prow'de means whereby, when an axle breaks, the

automatic air brakes on the vehicle and the brakes on the entire train, in which the vehicle is coupled as a unit, will be instantly applied.

It is an object of our invention to provide such means which will be inoperative during normal operation of the vehicle; but which will be made operative by the breakage or cracking of an axle, in operation.

It is a further object of our invention to provide means especially adapted for application to vehicles applied with braking systems, wherein reduction or release of air pressure in the air brake train line causes automatic operation of the brakes of the vehicle.

20 It is a further object of our invention to provide means including a chamber within the respective axles of the vehicle, which is filled with a non-corrosive low-resistance fluid, the escape of any of which fluid will cause a change of the re- 5 sistance of a circuit including the fluid, which change in resistance is utilized to cause release or reduction of pressure. in the vehicle train line, whereby to automatically cause application of the vehicle brakes.

30 It is a further object of our invention to provide such means which will operate, upon breakage or fracture of a vehicle axle, to cause automatic simultaneous operation of the brakes of all of the vehicles of the train.

35 It is a further object of our invention to utilize aWheatstone bridge having the resistances of the .respective vehicle axles included in the respective branches thereof whereby, upon a change of resistance in any axle, due to breakage, the Wheat- 40 stone bridge will be unbalanced and current will be caused to flow therethrough, which current is utilized to operate a relay, which relay, in turn, 'causes operation of a solenoid actuated or electro-responsive valve to release pressure in the 45 vehicle air train line, whereby to automatically apply the brakes of thevehicle.

It is a further object of our invention to provide warning means which is operated by the air escaping from the train line to designate the 50 vehicle in which the breakage has occurred.

It isa further object of our invention to provide warning means in the energizing circuit of the solenoid actuated 'or electro-responsive valve, whereby to indicate the vehicle in which axle 55 breakage has occurred.

It is a further object of our invention to provide such means for reducing the air brake train line pressure, whereby to automatically apply electromagnetic brakes in systems wherein such brakes are operated either alone or in conjunction with 5 vehicle air brakes upon reduction of pressure in the vehicle air train line.

It is a further object of our invention to provide means whereby the above objects may be achieved in brake systems including air brakes which are 10 applied automatically upon reduction of air train line pressure.

In the operation of railway vehicles, the fracture or rupture of an axle is .attended by damage to cargo, rolling stock and permanent way and often by personal injury or loss of life, and necessarily by delay and traflic congestirn. We propose to provide and utilize means cooperating with the several axles of a rail vehicle, which will operate, upon the occurrence of rupture or fracture of the axle, before the separation of parts occurs, to automatically and instantaneously apply the air brakes and/or, in some cases, the electromagnetic track brakes of the vehicle, as particularly described in our copendingapplications Serial No. 64,296 filed Feb. 1'7, 1936, and Serial No. 64,297 filed Feb. 1'7, 1936.

Referring to the drawings:

Figure 1 is a diagrammatic view of our invention, showing theWheatstone bridge, relay, solenoid actuated valve and connection to the air brake train line and other details of our invention:

Figure 2 is a partial diagrammatic view of the Wheatstone bridge shown in Figure 1, illustrating our method of connecting two vehicle axles in parallel in branches of the bridge, whereby to apply our invention to vehicles having more than four axles;

Figure 3 is a view similar to Figure 2, but showing our method of connecting the resistance elements of two axles in series in a branch of the Wheatstone bridge for the above purpose;

Figure 4 is a diagrammatic elevational view of our means for connecting the axle resistance elements in the branches of the Wheatstone bridge;

Figure 5 is a fragmentary detailed sectional view of the means shown in Figure 4, with one end of the axle broken away;

Figure 6 is a view similar to Figure 5, but showing a different embodiment of our means for connecting the axle resistance elements in the circuit of the Wheatstone bridge;

In the preferred embodiment of our invention,

- each axle is to be provided with a chamber which is filled with non-corrosive low-resistance fluid. Means is provided, whereby theresistance of this fluid may be inserted in a branch of a Wheatstone bridge and the respective branches balanced whereby, in the normal operation of the vehicle with all axles intact, no current will flow through the branches of the bridge, but wherein, upon breakage, rupture, or fracture of an axle, the escape of'fiuid which is the resistance element in one branch of the Wheatstone bridge, will cause, through suitable means, release of the normal air brake train line pressure in order that the air brakes or other brakes maybe instantaneously and automatically applied on the vehicleso equipped and/or on all vehicles of the train, depending upon whether the separate vehicles have separate air train lines or a common air train line therebetween. The unbalancing of the Wheatstone bridge causes the operation of a relay to complete the energizing circuit for a solenoid-actuated valve which operates, upon ener gization, to release the pressure: in the air. train line of the vehicle and cause a suitably attached whistle or siren to be sounded in order to designate the vehicle wherein axle breakage has occurred.

For the purpose of illustration, we disclose two means for connecting the resistance of the noncorrosive low-resistance fluid contained in the axle chamber into desired branches of the Wheatstone bridge. The first means comprises a suitable conducting terminal mounted on the axle and suitably insulated therefrom, which cooperates with a conducting ring or collector which is suitably insulated and supported by -bracket means to a desired part of the axle truck frame. (Figure 5). The second means comprises a suitably insulated terminal having one end in contact with the fluid in the axle chamber and the other end attached to a conductor ring suitably supported for rotation with the axle and insulated therefrom. The conductor ring is adapted to cooperate with a collecting shoe which is suitably attached by bracket means to any desired part of the axle truck frame. (Figure 6). -It is to be understood that we utilize the above described means in pairs and preferably situated at or adjacent the axle ends, and that we contemplate the use of other widely varying means which may be adapted to perform the same function.

Electrical mechanisms and connections Referring particularly to Figure 1 of the drawings, the Wheatstone bridge has the terminals A,

' B, C, D. The branch A--B includes the adjustable resistance element or rheostat l and the re-.-

sistance elementor resistor of the axle 2. The branch BC includes the adjustable resistance element or rheo'stat 3 and the resistance element of axle 4, and the branch C-D includes the adjustable resistance element or rheostat 5 and the resistance element'of the axle 6, while the branch D-A includes the resistance element of the axle I and the adjustable resistance element or rheostat 8. If desired, we may add a galvanometer 9 connected by the wire ID to terminal A and by wire II to terminal and preferably employ a switch 12 in the line II in order to normally disconnect the galvanometer 9 for a reason which will be obvious. the galvanometer will indicate whether'or not the branches AB, BC, CD and D-A are balanced, because, when they are unbalanced, current will flow through the branches as will be be closed.

When the switch I2 is closed,

As an alternate means of discovering whether or not thebranches are balanced, we may use a voltmeter I4 which may be connected by wire l5 to terminal A and bywire I6 toter-minal C. The difference in potential between points A and points C will denote an unbalanced condition which may be corrected by suitable adjustment of one or more of the adjustable resistance elements or rheostats I, 3, 5 or 8 in the respective branches of the bridge. In balancing the bridge, the resistances should be so adjusted that no potential difference will be registered by the voltmeter' I4 or,-in the case of the use of the galvanometer 9, so that, when the switchv I2 is closed, the galvanometer 9 will indicate a balanced condition.

In order to balance the branches of the bridge, it is necessary to energize the bridge and this is accomplished by connecting the terminal B by wire I! to switch terminal l8 of switch I9, and to connect the terminal D by wire 20 to the terminal '2I of the switch 'I9. The switch I9 has terminal 22 opposite terminal I8 and terminal 23 opposite terminal 2 I. The terminal 22 is connected by wire 24 to a terminal 25, which is connected by wire 26 to one terminal of a storage battery or other source of power 26a. The opposite terminal of the source of power 26a is connected by wire 2'! to a terminal 23. The terminal 28 is connected by wire 29 to the'switch terminal 23. When the switch I9 is closed, the path of currentis as follows: from the power source through wire 21 to terminal 28, through wire 29 to switch terminal 23, through switch I9 to terminal 2|, through wire 29 to terminal D of the bridge, through the parallel paths of the bridge, from terminal B of the bridge through wire II to switch terminal I8, through switch I9 to terminal 22, through wire 24 to terminal 25, and through wire 26 to the power source.

In order to utilize the current flow produced by change of resistance in any of the branches of the Wheatstone bridge, 'we have provided a relay, generally designated 30, which is energized for .a purpose which will be hereinafter described, by said current flow. The terminal A of the bridge is connected by wire 3|, switch 32 and wire 33 to a terminal of the solenoid 35 of the relay 30. The other terminal of the solenoid 35 is connected by means of wire 36, switch 31 and wire 38 to the terminal C of the bridge.

It will thus be seen that, when the switchv I9 is closed and the bridge balanced and energized, a change of resistance in any branch thereof, because of breakage in either. of axles 2, 4, 6 or 1, will, when switches 32 and 31 are closed as is theirnormal position, cause a current'flow from the terminal A through wire 3|, switch 32 and wire 33 to solenoid 35 and thence through wire 36, switch 31 and wire 38 to bridge terminal C and thence through the bridgeback to bridge terminal A. The relay 30 comprises a body 39, a solenoid chamber 40 and a switch upper end the armature 52 of the solenoid 85.

" Suitably attached to the lower end ofthe rod above.

or 'stem 5| is the switch contactor 48, described Interposed between the separating wall 49 and the contactor 48, about the stem 5|, is thespring 53, which is adapted, when the solenoid is de-energized, to hold the switch contactor 48 out of contact with switch contacts 44 and 45. Upon the energization of the solenoid 35 of the relay 38, the stem 5| is drawn upwardly against the force of spring 53, whereby the switchcontactor 48 bridges the switch contacts 44 and 45, whereby to complete the circuit therebetw'een. The solenoid 35 is energized, as pointed outabove, by the fiow of current in the branches of the Wheatstone bridge, A, B, C, D, by a change of resistance of one of the axles having their resistance elements connected therein, as pointed out above. The contact 45 is connected by the wire 54, which is connected at one end to the binding post 41, to one terminal of solenoid 1| of the solenoid-actuated or electro-responsive valve, generally designated 18. The other terminal of the solenoid H is connected by means of wire 55' to the above described terminal which, in turn, is connected to one terminal of the battery or source of power 26a. The other battery terminal is connected by wire 21 to terminal 28. The terminal 28 is connected by wire 56 to the binding post 45 of the contact 44. A buzzer 51 is connected in the energizing circuit for solenoid H as follows: one terminal of the buzzer 51 is connected by the wire 58 to the wire 54, the other terminal of the buzzer 51 is connected by wire 59 to the wire 55. Thus, when the solenoid H is energized, the buzzer 51 is op-,

erated.

When the solenoid of the relay 38 is energiz ed by flow of current in the Wheatstone bridge, as pointed out above, the stem 5| is drawn upwardly by the attached armature 52 against the pressure of spring 53, whereby the switch contactor 48 bridges contacts 94 and 45. The path of current from the source of power 28a is then as follows: from 25a through wire 21 to contact 28, through Wire 55 to contact 44, through contactor 48 to contact 45, through wire 54 to solenoid H, and back through wire 55 to terminal 25, and through wire 28 to the other terminal of the power source 28a.

will pass through wire 58 to buzzer 57, and thence through wire 59 to wire 55. Upon energization of the above-described circuit .of sole.- noid II, the solenoid-actuated or electro-re- ;sponsive valve device 78 releases the pressure in the air brake train line 85, as will be hereinafter fully described.

- Eiectro-pneumatic devices and connections is shown in Figure 1. When the above-described circuit is closed, current from wire 54' annular shoulder I1, which is formed on the in-. terior of the body 12. The chamber I5 is adapted to enclose the solenoid H and other parts of the solenoid valve actuating mechanism. Below the chamber 15 is the centrally disposed air outlet ichamber 18, which has the axially disposed valve cap member 14. A radially disposed valve inlet passage 82 leads from thechamber'lll to the outside of the body 12.. Centrally disposed within the lower cap member 18 is the valve seating and adjusting plug 83. The air train line 65 is connected by means of inipple 58,and pipe 81 to a nipple 84, threaded intovalve inlet passage 82. Threaded in the valve outlet passage 19 is a nipple 85,. which carries a pipe 86, to whichis suitably connected a whistle 'or siren 81. The wires 54 and 55, which are connected to the solenoid H, are insulated by means of suitable insulations 88 and 89 espectively, disposed in registering holes extending through the walls of body 12 and casting I6. 'Centrally,disposed in the bottom of casting 16 is a bore 98 which is disposed in alignment with a passage 9|, similarly disposed in the separating wall 88. The passage 9| terminates at its lower wall 88 in the frusto-conical valve seat 92. Disposed for reciprocation in passage 9| and bore 90 is a rod or stem 93, which carries, threaded at the top thereof, the armature 94 of the solenoid Also threaded on the stem 93, adjacent the,

armature 94, is the locknut 95, which is adapted to lock the armature in any desired adjustment on the stem 93. Suitably secured to. the lower end of the stem 93 is the valve member 98, which has a frusto-conical valve surface .91, which is adaptedto cooperate with the valve seat 92 to close the passageway 9|. On the lower surface of the valve 98 is a circular boss or projection 98, which acts as a spring guide. Disposed between the seat defined by the adjustable plug 83 and the lower surface of the valve 95 with its upper end disposed about the boss-or guide 98 is the spring 99, which is adapted normally to urge the valve 96 upwardly to close the passageway 9|.

The normal position of the parts 'of the electroresponsive valve or electro-pneumatic device I0 In the position of the parts there shown, the solenoid H is de-energized. The spring 99 urges the Valve '95 against its seat 92, thus preventing entry of air under pressure from trainlime 85, through pipe 81, and inlet passage 82 through inlet chamber 8| into passage. 9|.

Upon energization of the circuit including wires 54 and 55 and solenoid ll, as.described above, the solenoid H is energized and thrusts the valve stem 93 and valve 96 downwardly against the pressure of spring 99, whereby to allow air to pass from inlet chamber 8|, through passage 9|, into outlet chamber 78 and thence through outlet passage -'|9, nipple 85, pipe 88 and whistle 81 to the atmosphere. This releases or reduces the pressure in the air brake train' line, whereby the air brakes or, in some cases, the air brakes and/or the electromagnetic track brakes of the vehicle or train, which are connected to the air brake train line 85, are automatically applied.

In Figure 2, we have illustrated an adaptation of our invention to a vehicle having six axles,

wherein the electrical mechanisms and connections are the'same as those showndnFigure 1, the only diiference being that in branches A-B and BC respectively, an additional axle resistor or resistance element is connected in parallel with those of axles 2 and 4 respectively within the respective branches of the bridge, A, B, C, D. The means of connection is broadly similar to that disclosed in Figure 1, \the differences being apparent from examination of Figure 2.

In Figure 3, we have shown another adaptation of our invention to a vehicle having six axles, the resistors of additional axles in the branches AB and BC being connected in seriescwith those of axles 2 and 4 respectively, as will be obvious from examination of Figure 3.

The connection in the circuit of the resistance elements or resistors of the additional axles may be compensated for by proper adjustment of the adjustable resistance elements or rheostats 5 and 8 in the branches CD and'DA, in order to make the resistance value of the branch AB, BC, CD and D-A equal for the balanced condition of the bridge in normal operation. It is to be understood that, where it may be found desirable, we may use one bridge having four branches, such as that disclosed in Figure 1, to control the safety devices of any number of vehicles, where desired, by the connection of axle resistors or resistance-elements in any multiple of four or six in the respective branches of the bridge according to themanner disclosed in Figure 2, or that disclosed in Figure 3. It will thus.

be possible to use only a single Wheatstone bridge, relay and electro-pneumatic valve device for the control of automatic brake application in an entire train, wherein thecars have a single air train line, such as 65, in common.

Axle resistance. means and connections While we .contemplate the use of any desired type of resistance means on or within the respective axles of the train vehicle and any desirable means of connecting this resistance means to the respective branches of the Wheatstone bridge, we have shown in Figures 4, 5 and 6 two such means wherein the resistance of a non-corrosive low-resistance fluid contained in an axial chamber in the axle is connected into a desired branch of the Wheatstone bridge, according to the teachings of Figure 1, Figure 2 or Figure 3.

With reference particularly to Figure 5, an axial chamber I03 extends throughout the length of the axle 2 and therewithin. The ends of the chamber are closed by suitable plug members I04. Disposed adjacent the ends of the axle are threaded holes I05 adapted to receive plugs I06 I of suitable insulating material. The plugs I06 have the lower ends thereof threaded on the outside for engagement with the threads in the holes I05 and'have enlarged cylindrical upper ends which are separated from the threaded portions by the shoulder II, which is adapted to engage an annular flat spotor face I08 on the'axle 2 adjacent the hole I05. The plugs I06 and other parts of the structure disposed at opposite ends of axle 2 in Figure are identical, and only one need be described. Each plug I06 is adapted to receive and supporttherein a conducting terminal IIO, which is received in a central stepped bore in the plug I06. The enlarged or head portion of the conducting terminal H0 is screwthreaded in the upper portion III of this bore,

while the cylindrical portion H2 or the terminal IIO extends through a central bore H3 and the lowest and smallest bore II4, through which it projects into the chamber I03 and the fluid contained therein. Suitable packing H5 is disposed within the central bore H3 of the plug I06 in order to prevent the leakage of the fluid con- .tained in chamber I03.

- It-will thus be seen that the conducting terminal H0 is rigidly supported for rotation on the axle 2 and is entirely insulated therefrom by the plug I06. As itis well known that electrical current will follow the line of least resistance, it will be understood that the path from one conductor terminal I I0 through axial chamber I03 and to the, other conductor terminal IIO of the axle 2 provides the path of least resistance from terminal to terminal and that electrical power will, by following the line of least resistance,

travel therethrough.- Suitably supported about the'axle 2 and surrounding the conductor terminal IIO for slidingor brushing contact there with is the conducting ring or collector ring H6. The collector ring H6 is suitably mounted .in a surrounding or insulating ring II I, which is made of insulating or non-conducting material. The insulating ring 1, which is integrally attached to the collector ring 6, is non-rotatably supported by any suitable bracket means, designated H9, on any desired part of the axle truck frame. Leading from one of the collect- I i-ng rings H6, shown in Figure 5, is a wire I III,

IM to collecting'ring H6 and thence through conducting terminal IIO into the fluid in chamber I03 and thence through the second conductor terminal IIO to collecting ring H6 and thence through-wire I 02'to point B. Like circuits between the axles, and'the other branches of the bridge are contemplated, and the path of the circuit from A to C in either path will be obvious from inspection of Figures 1, 2, 3 and 4.

With reference to Figure 6, we have shown a second embodiment of our invention, wherein the insulating plug I06, screw-threaded into axial Hole I05 in the axle 2, isof substantially cylindrical shape having the top portion and top threaded bore omitted therefrom. Disposed about the axle 2 is an insulating band or ring I20 which has suitably received therein and sup-'-."

ported thereby an annular conductor ring I2l, which is made of suitable conducting material.

The conductor ring I2I has a threaded hole I23.

extending radially therethrough and in align ment with the bore I22'of the insulating ring, I20 and with the bores of the insulating, plug I06. The conductor terminal H0 is adapted to extend through the threaded hole IN, the bore I22 and the central bore of insulating plug I 06 so that its cylindrical end portion '2 extends into the axial passage |03 of the axle 2. Tha upper,'en-

larged portion or head of the conductor terminal H0 is screw-threaded in the threaded hole I23 in the conductor ring I2I. Suitable packing H5 brakes.

is disposed within the counterbore of the insulating plug I 06. Any suitable brush, shoe, or collecting device may be utilized to keep the wire [0| electrically connected to the conductor ring l2! during rotation of the axle. The path of electrical power in the embodiment disclosed in Figure 6 will be, as in Figures 4 and 5, from wire I 0| through the brush or collector It" to and through conductor ring HI and conductor terminal llll into the fluid in axial chamber I03 and thence through the other conducting terminal l III to the second conductor ring and thence to the second brush or shoe and to wire I112. The connection of each axle resistor in the respective branches of the Wheatstone bridge is the same as that described above.

It-is, of course, understood that the switches 32 and 31 respectively may be omitted from the lines, in which they are shown and that the operation of balancing the branches of the Wheatstone bridge, preliminary to normal operation, may be carried out although the change of the resistance in any of the four branches of the Wheatstone bridge by adjustment of the rheostats I, 3, 5 or 8, will cause application of the With the use of the switches 32 and 31, this brake application is prevented during adjustment of the brakes.

A particular advantage of our invention is dependent upon the fact that the formation of a slight fissure or crack in an axle will cause a changein the resistance of the fluid in the axle chamber I03, whereby to cause automatic operatiori of the air brakes and/or electromagnetic track brakes before serious damage has occurred, by reason of total. separation of the axle stubs at either side of the crack or fissure. Furthermore, upon the operation of the brakes, the particular axle which, by cracking, has caused the operation, may be located by adjustment of the adjustable rheostats I, 3, 5 and 8 of the Wheatstone bridge, whereby to ascertain in which branch the resistance has been increased.

This latter branch will be that branch which in-' cludes the axle which has cracked orbegun to crack.

It will be understood that the above description is illustrative and in no wise limiting. and that the structure, which may be used in the practice of our invention, is susceptible of variation within wide limits and that we desire to comprehend within our invention such modifications as may be necessary to adapt it to varying conditions and uses and which may be embraced within the claims and the scope of our invention.

Having thus fully described our invention, what we claim as new and desire to secure by Letters Patent, is: r

1. A safety device for a rail vehicle having an axle, an air train line, and brakes adapted to be automatically applied upon decrease of pressure in the train line, said-device comprising electri- 'cal resistance means. in said-axle adapted to be increased upon breakageof the axle and means adapted upon increase-oLsaid resistance means to cause decreaseof pressure in said airtrain line, whereby to cause automatic operation of the brakes.

2. A safety device for a train comprising rail vehicles having axles, a common air train line,

and brakes adapted to be automatically applied upon decrease of pressure in the train line, said device comprising electrical resistance means in one of said axles adapted to be increased upon breakage of the axle and means adapted upon increase of such resistance means to cause decrease in the pressurein saidiair traindine, whereby tocause automatic. operation ofthe brakes on each vehicle in the.:traim when breakage of said axle occurs.

3. A'safety deviceifor a rail vehicle having an axle, an air traimlineaand' brakes adapted to be: automatically, appliedi upon; decrease of pressure: in the train line,- said? device.- comprising a re:- sistance element in said ax1eadapted to be in;- creased upon rupture: of said axle a Wheatstone bridge having: said, resistance element in one branch thereof. and? adapted to be.unbalanced by increase of said. resistance element, and meansadapted. to be operated by unbalancing ofsaid: Wheatstone bridge: to. decrease. the pressure in. said air train line,, whereby to cause automatic: operation of said; bnakes.

4. A safety devicerfor a train comprising i rail. vehicles having an axle, a common air train line,

. and brakes. adapted to be automatically applied upon decrease of pressure in the train line, said device comprising; a resistor in one of said axles adapted to have its: resistance increased upon rupture of said axle, a Wheatstone bridge.having the said resistor in one branch thereof and adapted to be unbalanced by increase of the resistance of said resistor, and means adapted to be operated by unbalancing of said Wheatstone bridge to decrease the pressure in said air P train line, whereby to cause automatic operation of said brakes.

, 5. A safety device for a rail vehicle having an axle, an air, train line, and brakes adapted to be automatically applied upon decrease of pres- 3 brakes, said last-named means including a. relay adapted upon unbalancing of said Wheatstone bridge to energize. an electro-pneumatic device adapted, uponenergization, to decrease the pressure in said air train line. 4

6. A safety device for a train comprising rail vehicles having an axle, a common air train line,-

and brakes adapted tobe automatically applied upon decrease of pressure in-the train line, said device comprising-a-resistor in one of said axles 4 adapted to have its resistance increased upon rupture of said axle, a Wheatstonebridge having the said resistor in one branch thereof and" adapted to be unbalanced by-.increase of, said resistance,- and means adapted to be operated by unbalancing of said Wheatstonebridge to decrease the pressure in 'said air ,train line,

whereby to cause automaticoperation of saidbrakes, said last-named; means including a relay adapted, upon unbalancing of said Wheatstone bridge, to energize an electro-pneumatic device adapted, upon energization, to decrease the pres-,-

sure in said air train line.

7. In a safety device for a train vehicle having axles; an air brake train line, and brakes adapted to be automatically applied upon 'decrease of pressure in the train line; a Wheatstone bridge adapted to be unbalanced by increase of the resistance of aresistance element due to breakage of an axle' carrying said re- Wheatstone bridge when unbalanced to reduce the pressure in said train line, whereby to cause automatic application of said brakes on' the occurrence of axle breakage.

8. In a safety device for a rail vehicle having axles, an air brake train line, and brakes adapted to be automatically applied upon decrease of pressure in the train line; a Wheatstone bridge adapted to be unbalanced by increase of the resistance of a resistance element thereof due to breakage of an axle carrying said resistance element, and means operated by said Wheatstone bridge, when unbalanced, to reduce the pressure in said train line and operate a warning signal whereby to cause automatic application of said brakes and indicate the occurrence of axle breakage.

9. In a safety device for a train comprising rail vehicles having axles, a common air train line, and brakes adapted to be automatically applied upon decrease of pressure in said air train line; a Wheatstone bridge adapted to be unbalanced by increase of the resistance of a resistance element therein due to breakage of an axle carrying said resistance element, and means operated by said Wheatstone bridge when unbalanced to reduce the pressure in said train line whereby to cause automatic application of the train brakes on the occurrence of axle breakage in the train. a

10. In a safety device for a train comprising rail vehicles having axles, a common air train line, and brakes adapted to be automatically applied upon decrease of pressure in said air train line; a Wheatstone bridge adapted to be unbalanced -by increase of the resistance of a resistance element therein due to breakage of an axle in the train carrying said resistance, and means operated by said Wheatstone bridge, when unbalanced, to reduce the pressure in said common air train line and operate a warning signal, whereby to cause automatic application of said train brakes and indicate the vehicle in which axle breakage has occurred.

11. In a safety device for a rail vehicle having axles, an air brake train line, and brakes adapted to 'be automatically applied upon decrease of an axle containing said resistance to' cause said relay means to close said energizing circuit, whereby to cause automatic application of the vehicle brakes upon the occurrence of axle breakage in the vehicle. i

12. In a. safety device for a rail vehicle ha axles, an air brake train line, and brakes adapted to be automatically applied upon decrease of pressure in the train line; means adapted upon the occurrence of axle breakage to cause automatic application of the brakes, said means comprising an electro-pneumatic valve device adapted when energized to release the pressure in said air brake train line and operate a warning signal, an

energizing circuit for said electro-pneumatic valve device, relay 'means for closing said circuit, and a Wheatstone bridge adapted to be by sistance element, and means operated by said increase of the resistance-of a resistor thereof due to breakage of an axle containing said resistance to cause said relay means to close said en- I ergizing circuit, whereby to cause automatic application of the vehicle brakes and operation of the warning signal upon the occurrence of axle breakage in the vehicle. 4

13. In a safety device for a train comprising rail vehicles having axles, a common air train relay means to close said energizing circuit,

whereby to cause automatic application of the train brakes upon the occurrence of axle breakage in the train.

14. In a safety device for a train comprising rail vehicles having axles, a common air train line,

and brakes adapted to be automatically applied upon decrease of pressure in said air train line; means adapted upon the occurrence of axle breakage to cause automatic application of the brakes,

said means comprising an electro-pneumatic valve device adapted when energized to release the pressure in said common air train line and operate a warning signal, an energizing-circuit for said electro-pneumatic valve device, relay means for closing said circuit, and a Wheatstone bridge adapted upon increase of the resistance of a resistance element thereindue to breakage of an axle carrying said resistance element to be unbalanced and cause said relay means to close said energizing circuit, whereby to cause automatic application of the train brakes and operation of the warning signal upon the occurrence of axle breakage in the train to stop the train and,

designate the vehicle thereof in which axle bre'akage has occurred.

l5. Ina safety device for a rail vehicle havin axles, an air brake train line and brakes adapted to be automatically applied upon decrease of pressure in the train line; electro-pneumatic means adapted upon energization to release the pressure in said air train line and electrical means adapted upon change of resistance of a resistor therein due to breakage of a vehicle axle contain-. ing said resistor to energize said electro-pneumatic device, whereby to cause automatic application of the vehicle brakes upon breakage of an axle thereof, said resistor comprising low resistance fluid contained in said axle and adapted,

- upon occurrence of axle breakage, to leak out and increase the resistanceof said resistor.

'16. In a safety device for a traincomprising rail vehicles having axles, a common air train line, and brakes adapted to be automatically applied upon decrease in pressure in said common air train line; electro-pneumatic means adapted upon energization to decrease the pressure in said common air train line, and electrical means adapted upon unbalancing of resistors therein due to breakage of an-axle in a vehicle of the train carrying one of said-resistors in the form of a confined low resistancefluid to energize said electro-pneumatic device, whereby to cause autoage of an axle in the train.

17. In a safety device for a train comprising rail vehicles having axles, a common air train line and brakes adapted to. be automatically applied upon decrease in pressure in said common air train line; electro-pneumatic means adapted upon energization to decreasethe pressure-in said common air train line, and electrical means adaptedupon breakage of anaxle in a vehicle of the train to energize said electro-pneuniatic device, said electrical means including a Wheatstone bridge and a resistance element in each axle inserted in a branch thereof, whereby upon breakage of an axle the bridge will be unbalanced and cause energization of 's,ai d electropneumatic device to automatically apply the train' brakes.

18. Ina safety brake applying device for a rail vehicle comprising electrical means adapted upon increase of the resistance of a resistor to cause automatic application of the vehicle brakes; said electrical resist-or comprising a fluid-containing chamber in a vehicle axle, whereby uponbreakage of the axle the escape of fluid will increase the resistance of the resistor and cause automatic application of the vehicle brakes.

19. A rail vehicle brake applying device comprising an electro-pneumatic device adapted. upon energization to cause automatic application of the vehicle brakes, an electrical means adapted upon breakage of a vehicle axle to cause energization of said 'electro-pneumatic device}; said electrical meanscomprising a Wheatstone bridge adapted upon being unbalanced to energize said electro-pneumatic device, fluid resistance elements in the vehicle axles, and meansfor connecting the fluid're'sistance elements of the r0- tating axles in branches of said Wheatstone bridge. 7

20. A rail vehicle brake applying device comprising an electropneumatic device adapted upon energization to cause automatic applica-- tion of the vehicle brakes, and electric means adapted upon breakage of a vehicle axle to cause energization of said electro-pneumatic device; said electrical means comprising a Wheatstone bridge adapted upon being unbalanced to energize said electro-pneumatic devices, fluid resistance elements in the vehicle axles, and means comprising conducting terminals mounted on and insulated from the respective axles in contact with the fluid, and collector rings in brushing contact with said terminals and being connected by wires into said branches of the Wheatstone bridge. r

21. A rail vehicle brake applying device comprising an elastic-pneumatic device adapted upon .energ ization to cause automatic application of the vehicle brakealan electrical means adapted uponbreakageof a'vehicle axle to cause energization of said .electro-pneumatic device; said electrical means comprising a Wheatstone bridge adapted upon being unbalanced to energize-said device, fluid resistance elements in the "vehicle axles, and -means for connecting'the .fluid resistance elements of 1 the rotating axles in branches of said Wheatstone bridge, said last-' named" means comprising conducting terminals having one end in contact'withthe fluid'and the other rigidly attached to'a conductor ring rigid-.

-1y mounted on an axle and insulated therefrom,

22. A'rail vehicle brake applying device comprising an electro' pneumatic device adapted upon energization to cause automatic application of the vehicle} brakes, an electrical means adapted upon-breakageoi' a vehicle axle tocause energization of'said electro-pneumatic device; said electrical means comprising a Wheatstone .{bridge adapted'upon being unbalanced to energize-saidde ."vehicle'axles aijidmeans for connecting the fluid resistance "elements of the rotating axles in branches of said Wheatstone bridge, said laste, fluid resistance elements in the named 7 means. comprising conductor means mounted for rotation with the axles having con-- tact-withthe fl'uid and insulated from the axle, and collector means having brushing contact with; said conductor means and being attached byjineans' oi wires in a branch of the Wheatstone bridge.

23. In a braking system for a railway vehicle, an electrical circuit, an axle carrying a resistance element connected in said electrical circuit and adapted to have its resistance changed by axle breakage, and means associated with said electrical circuit for applying -the breaks of said system when the electrical system is disturbed by changing the resistance of the resistance element in the axle.

24. In a braking system for a vehicle including a plurality of axles'carryi-ng resistors adapted to havetheir resistances changed by axle break 1 age, said resistors being electrically connected ina balanced Wheatstone bridge, said bridge being adapted when an axle is broken to become unbalanced, means adapted upon unbalancing of said bridge to cause operation of the brakes'of said system, and means of indicating said unmeans adapted. to be inoperative when said Wheatstone bridge is balanced and to operate upon the unbalancing thereof, due to the change of the resistance of the axle resistance element,

to cause application of the brakes of the braking system.

27. In a braking system .for a railway vehicle,

an axle havingaa fluid resistance element therein and adapted to have its value changed by axle rupture, and means adapted to operate upon change of value of said axle resistance element said system.

-28. In a braking system for a rail vehicle having a-plurality of axles carrying fluid re-f slstors adapted to have their resistances changed by axle breakage, circuit'means for electrically connecting the resistors oisaid axles in a balanced Wheatstone bridge, and means adapted upon the unbalancing ofsaid bridge to cause a plication 'of. the brakes of said system, said last-named means including means for indicating the unbal anced condition of said bridge.

29. In a braking system fora rail vehicle having a plurality ofaxles carrying fluid resistors adapted to have their resistances changed by 60 to cause automatic application of the brakes of ing a plurality of axles carrying fluid resistors axle breakage, means for electrically connecting adapted to have their resistances increased-by axle breakage and being electrically connected together in a balanced Wheatstone bridge circuit,

. means adapted to operate upon unbalancing of I said circuit due to axle breakage to cause automatic, emergency application of the brakes of said braking system.

THEODORE H. SCHOEPF.

DAVID M. RITCHIE.

CPI 

